Improvement in screw-drivers



w. F. PATTERSON.

Screw-Drivel. I

N,0.i63,401 PatentedMayl8,1875.

Fig.1.

UNITED STATES PATENT OFFICE.

WILLIAM F. PATTERSON, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN SCREW-DRIVERS.

Specification forming part of Letters Patent No. 1 63,401, dated May 18,1875; application filed April 27, 1875.

To all whom it may concern:

Be it known that I,WILLIAM F. PATTERSON, of Boston, in the county ofSuffolk, State of Massachusetts, have invented a certain new and usefulImprovement in Screw-Drivers, of which the following is adescriptionsufficiently full, clear, and exact to enable .any person skilled in theart or science to which my invention appertains to make and use thesame, reference being bad to the accompanying drawing forming a part ofthis specification, in which- Figure 1 is an isometrical perspectiveview, showing the clamp as arranged for using the central blade. Fig. 2is a sectional perspective view, showing one of the auxiliary bladesadvanced for use 5 and Fig. 3, an isometrical perspective view of theclamp detached.

Like letters of reference indicate corresponding parts in the differentfigures of the drawmg.

My present invention is designed as an improvement on the screw-driversdescribed in five several Letters Patent of the United States heretoforeissued to me, and numbered respectively, February 24, 1874, No. 147,785November 24, 1874:, No.'157,102; January 19, 1875, No. 158,807; March 9,1875, No 160,543; March 23, 1875, No. 161,056 and consists in a novelconstruction and arrangement of the parts, as hereinafter more fully setforth and claimed, by which a more effective implement of this characteris produced than is now in ordinary use.

The nature and operation of my invention will be readily understood byall conversant with such matters from the following descriptlonz In thedrawing, A is the haft or handle, and B the main or central blade.Pivoted at E to the main blade B, in such a manner as to have a commoncenter of motion, there are two auxiliary or supplemental blades, D 0,

provided at their bases with the tenons G, the main and auxiliary bladesbeing correspondingly nicked or laterally grooved at F. A clamp, I,having the internally-arranged slots H, is fitted to slide over theblades, and is provided with the eccentric shaft J. This shaft extendslaterally through the clamp at one of the apertures or mortises in whichthe blades fit, and is so constructed that it may be turned to projectits eccentric or rounded side 11. into the mortise, or to bring itsflattened side m flush with the side of the same, as desired, the nicksFf being designed to receive the shaft when so turned as to project intothe mortise.

In the use of my improvement when the supplemental blades are notrequired they are reversed, as shown in Fig.1, bringing their pointsnearest the haft A, in which position they are secured by turning theshaft J, so as to bring the part a into the nick f at the base of themain blade. In case either of the anxiliary blades are required, theparts are arranged as shown in Fig. 2, in which the tenon Gr 0f theblade 0 is inserted in the slot II, and

all of the blades clamped together or secured I by turning the shaft Jinto the slots F.

I do not herein claim anything shown or described in either of saidLetters Patent when in and of itself considered; but

Having thus explained my improvement, what I claim is In a screw-driver,substantially such as described, the blade B, provided with thereversible auxiliary blades 0 D, and the clamp I, provided with themortise H, and the eccentric shaft J, all constructed and arranged tooperate substantially as and for the purpose set forth and specified.

WILLIAM F. PATTERSON.

Witnesses:

H. E. METGALF, GEo. G. SHAW.

